Conventionally weed growth is controlled either by use of herbicide chemicals which are applied to the weeds by spraying or in the form of powder or granules which are sprinkled about the weeds, or alternatively by physically uprooting the weeds.
Physically removing the weeds is time consuming and labour intensive. Herbicides can be relatively expensive, and there is increasing resistance to the use of such synthetic chemicals in the environment particularly in terms of spray drift or in the seepage of such chemicals into the watertable or water supply areas. The control of roadside berms has previously been carried out by the continuous application of herbicide sprays (typically a glyphosate spray) from a moving vehicle (or in some cases from a backpack spray).